theypsilon / concat Goto Github PK

concat(1,2,3,std::endl); // error: requires 3 arguments, but 4 were provided

It looks like is not possible to infer between the char version of std::endl and wchar_t, and therefore it displays that weird error message. Because a parameter pack is used in order to allow variadic parameters with perfect forwarding, I see no way to help the compailer to infer the std::endl type in a arbitrary position of the parameter list.

std::ostream& (*s)(std::ostream&) = std::endl;
std::cout << concat(1,2,3, s);

works as expected, but doesn't feel right.

C++11 added get_money, put_money, get_time and put_time, but they are not yet handled as manipulators (this means, they will introduce a separator when a separator is noticeable).

Is it possible to implement is_parametrized_manipulator without having to list all the parametrized manipulators from here?

Currently only covering std::setprecision is covered, and would be necessary to have all the other parametrized manipulators in the test suite.

So now that std::pair is supported, it would be great to be able to have different delimiters at the start/end of sequences in addition to between the elements of a sequence, so a list of tuples might be rendered like:

(1, 2, 3), (3, 2, 1), ....

Otherwise there's no way to distinguish this:

list<int> ints ({1, 2, 3, 4, 5, 6})
cout << concat (separator (","), ints) << "\n";

from this:

list<pair<int, int>> pairs ({{1, 2}, {3, 4}, {5, 6});
cout << concat (separator (","), pairs) << "\n";

I think you're trying to keep things simple, so perhaps this is a feature too far.